Mercury switch



March 5, 1935.

c. J. WARNKE 1,993,046

MERCURY SWITCH Fiied April 29, 1935 tain gases have amazing. dielectric properties and fold. Actual tests have proven this statement Patented Mar. s, 1935 1,993,046

UNITED STATES: PATENT OFFICE MERCURY SWITCH Carl J. Warnke, Elkhart, Ind., alsignor, by direct and mesne assignments, to The Adams & Westlake Company, Chicago, 111., a corporatlon of Illinois Application April 29, 1933, Serial No. 668,496 Claims. (01. 200-152) This invention relates'to-mercury switches and switch electrodes. As a consequence, the elecparticular-Iv to the chemical composition of the trodes do not wear away or deteriorate with use. constituent elements of the switches. In my United States Letters Patent No. 1,883,- The principal object of the invention is to pro- 146, issued Oct. 18, 1932, I disclosed the fact that 5 vide a' switch which, because of the materials mercury switches filled with hydrogen which had 5 that are used and their relationship to each other, been purified in a certain manner, had twice the will long outlive the ordinary switch. life of ordinary switches. The X gases, when 0f prime importance is the gas fill which I use used in mercury switches, do infinitely more; they in the switch envelope. I have found that cerlengthen the useful life of the switches a thousand are far more inert and resistant to ionization to be a fact.

than hydrogen, or any of the other gases com- The amazing action of the X gases is further monly used in mercury switches. demonstrated by tests that were made with four For example, a hydrogen-filled switch made in switches identical in all particulars except the accordance with approved manufacturing'practice gas fill. In switch No. 1, purified hydrogen was may have a maximum useful life of 4000 cycles used; in switch No. 2, helium; in switch No. 3, a

of operation under given conditions of load, physical mixture of helium and hydrogen; and

whereas a switch made in accordance with this No. 4, one of the X gases (helium hydride). All

invention, and operating under the same load, switches were subjected to the same load, and it has been put through more than five million was observed that afterashort time, switch No. 1 20 cycles of operation without any marked sign of was warm; switch No. 2 was hot; switch No. 3 was deterioration. This remarkable demonstration of warmer than switch No. 1, but not as hot as switch endurance shows clearly that a vastly improved No. 2; and that switch No. 4 showed no signs whatswitch has been made, and I believe that its soever of being heated.

superiorityislargely due to the unusual properties As the X gases are not absorbed by and do 25 of the gases which I use for fills. not react with the electrode materials, it follows In brief, I have discovered that certain gases that the surfaces of the electrodes are always. are infinitely more suitable for gas fills in mercury clean and consequently a good contact is always switches than the gases nowused; also I have assured. Furthermore, as a film cannot form on found that these gases are employed to the best the surfaces of the electrodes in the presence of 30 made a part of the disclosure of this application, pose of disclosure only. Preferably, the glass enadvantage when the other constituents of the the X gases, the contact resistance of the switch are made of certain materials that do not switch does not increase with use.

react with each other, or with the gas 1111 of the Further and other objects and advantages will r Sw tch. become apparent as the disclosure proceeds and J In myPatent No. 1,96752 issued July 24, 1934, the description is read in conjunction with the 35 I have disclosed a method and apparatus for accompanying drawing, in which producing gases having substantially greater Fig. 1 is a diagrammatic view showing the resistance to ionization than hydrogen and being method which I employ for filling mercury relatively incapable as compared with hydrogen switches with 11" gases; and of reacting with or being absorbed by such metals Fig. 2 is a longitudinal, sectional view showing as platinum, tungsten, molybdenum, tantalum one type of mercury switch to which this inven- -and vanadium. These gases, I believe to be hytion is applicable. drldes of helium, neon, argon, silicon, and boron, The mercury switch which has been shown is andinthe companion application, which ishereby but one of many types, and is used for the pur- I have given evidence to substantiate my belief. velope 10 is made of magnesium-silicate glass But whatever the chemical composition of these that is substantially free from lead, tin. antigases, it is a proven tact that they greatly lengthmony, and other substances which decompose en the life of the switches and improve their under the action of an electric arc. Both other operating characteristics. glasses such as hora-silicate glass may be used These new and improved gases. which for coninstead. venlencewill be called X gases, have other in- A pair of leads 11 and 12 are sealed through teresting and useful properties. Because of their one end of the envelope and these leads may be complete, or substantially complete inertness, they of molybdenum, tungsten, or any other suitable donut react with, nor are they absorbed by the material.

The inner ends of the lead-in conductors are equipped with electrodes 13 and 14 which may be of platinum, tungsten, molybdenum, tantalum, vanadium, or any other suitable material.

A quantity of mercury 15 is placed in the envelope prior to sealing and is adapted to make or break an electrical circuit through the electrodes according to the position of the switch. The mercury is purified prior to being introduced into he envelope to remove all traces of oxides, water zapor, carbo-hydrates, and other impurities which decompose under the action of the electric arc.

Before the switch envelope is sealed off as indicated at 16, it is exhausted and filled with one of the X gases, and I prefer to use the gas that is formed by passing helium and hydrogen through my apparatus as disclosed in my Patent No. 1,967,952 which constitutes a part of this disclosure.

The method which I use for exhausting the envelope and filling it with an X gas is shown in Fig. l. The container 17 preferably contains a physical mixture of helium and hydrogen in the proportion of two volumes of helium to one volume of hydrogen. The top of the container is connected by a tube 18 with the apparatus 19 that converts the helium and hydrogen into What I believe is helium hydride. The outlet 20 of the apparatus is packed with cotton 21, or other filtering material acting merely to prevent the precipitated solids entrained in the purified gas from being carried into the switches.

A high vacuum pump 22 is provided for exhausting the switch envelope 10 and this is connected with the envelope by turning the stop cook 23 to a position in which the passages 24 and 25 communicate with the tube 26 leading to the vacuum pump 22, and the tubulature 27, connected by the rubber hose 28 to the top of the switch envelope, respectively. When the stop cook 23 is in this position, the switch envelope is closed to the apparatus 19'.

After the envelope has been thoroughly exhausted (the envelope should be heated during evacuation to remove occluded gases), the stop cook 23 is turned to a position in which the passage 25 communicates with the outlet 20 of the apparatus 19 and the passage 24 communicates with the tubulature 27. A valve 29 in the outlet 20 regulates the flow of gas from the apparatus and the pressure in the envelope may be measured by the pressure gauge 30. As soon as the switch envelope is placed in communication with the apparatus, the gauge 30 immediately drops to approximately a zero reading and thereafter slowly rises as gas is admitted through the valve 29 into the envelope. When the proper pressure has been reached, preferably about five inches less than atmospheric pressure, the stop cook 23 is turned to the position shown in Fig. 1 and the top of the switch envelope is then sealed off to complete the switch.

Under some conditions of use, inferior materials may be substituted for certain components of the switch in order to cut down the cost of manufacture, and it will be understood that this invention is not limited to the use of the preferred materials conjointly. But for best results, the preferred materials should be used.

What I claim, therefore, is:

1. In a mercury switch, a glass envelope, spaced electrodes in the envelope, a quantity of mercury in the envelope adapted to be manipulated to make or break an electrical circuit through the electrodes, and a gaseous hydride of the inert gases in the envelope.

2. In a mercury switch, a glass envelope, spaced electrodes in the envelope, a quantity of mercury in the envelope adapted to be manipulated to make or break an electrical circuit through the electrodes, and a gas fill of helium hydride.

3. In a mercury switch, a glass envelope, spaced electrodes in the envelope, a quantity of mercury in the envelope adapted to be manipue lated to make or break an electrical circuit through the electrodes, and an inert arc suppressing gas in the envelope formed by passing a mixture of helium and hydrogen through an electric arc in the presence of one or more ionized hygroscopic metals.

4. In a mercury switch, a glass envelope, spaced electrodes in the envelope, a quantity of mercury in the envelope adapted to be manipulated to make or break an electrical circuit through the electrodes, and an inert arc suppressing gas in the envelope formed by passing a mixture of helium and hydrogen through an electric arc in the presence of ionized titanium and one or more strongly hygroscopic metals.

5. In a mercury switch, a glass envelope, spaced electrodes in the envelope, a quantity of mercury in the envelope adapted to be manipulated to make or break an electrical circuit through the electrodes, and an inert arc suppressing gas in the envelope formed by passing a mixture of helium and hydrogen through an electric arc in the presence of sodium and titanium ions.

CARL J. WARNKE. 

